Effect of a fixed dorzolamide\\Ntimolol combination on intraocular pressure after small-incision cataract surgery with Viscoat

Abstract

The effect of a fixed dorzolamide-timolol combination (Cosopt) on intraocular pressure (IOP) after small-incision cataract surgery with sodium chondroitin sulfate 4%-sodium hyaluronate 3% (Viscoat) was evaluated in a prospective, randomized study. Seventy-six eyes of 38 patients scheduled for small-incision cataract surgery in both eyes were randomized to receive 1 drop of dorzolamide-timolol in one eye or no treatment immediately after surgery. The fellow eye received the other assigned treatment following surgery at a later date. Small-incision cataract surgery was performed with sodium chondroitin sulfate 4%-sodium hyaluronate 3% in an identical fashion in both eyes. The baseline IOP was measured by Goldmann applanation tonometry 1 day before surgery and 6 hours and 20 to24 hours after surgery by a masked observer. The intraocular pressure was measured by Schiotz tonometry at the conclusion of the case and was adjusted to 20 mm Hg. Six hours after surgery, the mean increase in IOP was significantly lower in the dorzolamide-timolol group than in the control group (4.3 + 5.6 mm Hg vs 8.4 + 6.1 mmHg, respectively; p= 0.003). Two eyes in the dorzolamide-timolol group had IOP spikes of 30 mm of higher vs 9 eyes in the control group (p = 0.022). Twenty to 24 hours after surgery, the mean IOP change was -2.6 + 3.3 mm Hg in the dorzolamide-timolol group vs 1.5 + 3.2 mm Hg in the control group (ph 0.001). A single topical drop of dorzolamide-timolol was effective in reducing IOP 6 hours and 20 to 24 hours after cataract surgery, and it reduces, but does not eliminate, the risk of sodium chondroitin sulfate 4%-sodium hyaluronate 3%-induced IOP spikes of 30 mm Hg or higher. Michael D. Wagoner.